The aim of this research is to determine the nature and extent to which grafted skin assumes the sensory characteristics of the recipient site as compared to the sensory characteristics of the donor site. Such information is of immediate use in the clinical setting especially when information of the temporal aspect of the recovery of sensation is also traced. From the standpoint of basic neuroscience, it may be possible, using skin grafting as a vehicle, to manipulate innervation density with the aim of better defining its role in cutaneous sensitivity. The role of specialized receptors of glabrous skin in cutaneous sensation may also be inferred from a characterization of the sensory capacities of grafted skin. The evidence presently available seems to indicate that the structural characteristics of a graft remain relatively faithful to the donor site. Furthermore, the dorsal root ganglion cells appear not to be able to initiate epithelial differentiation to produce new complex (encapsulated) receptive structures, although there is some question about the Merkel neurite complex. Proposed here are a longitudinal paradigm that will trace the nature, extent, and time course of the return of sensations to grafted skin and a cross sectional study designed to sample, in different subjects, the extent of sensory return as a function, primarily of graft age and type of graft employed. A new generation of instruments has been developed, built, and interfaced with a computer that controls the functions of most of the instruments, as well as analyzing the data, on line. The tests consist of measuring density and thresholds of "touch spots" and "mechanically induced pain spots," tactile sensitivity over a larger area (2.9 square cm.), vibratory sensitivity at 40 and 250 Hz, density of warm and cold spots, warm and cold sensitivity, over a larger area (7 square cm.), density of heat induced pain spots, heat induced pain sensitivity over a larger area (7 square cm.), point localization and the two-point limen. Devices will also be developed to assess active touch in normal and grafted skin on fingers.